Table 2. Calculated MP2/6-311++G(d,p) Energetic and Spectroscopic Data of Low Energy Conformers of 2ATFME.
| 1a | 1b | 2a | 2b | 2c | 2d | 3a | 3b | |
|---|---|---|---|---|---|---|---|---|
| ΔEa | 0 | 5.3 | 18.7 | 13.1 | 9.1 | 11.4 | 16.6 | 22.6 |
| A/MHz | 3008.209 | 3401.083 | 2882.240 | 2931.942 | 3307.363 | 3298.423 | 2670.287 | 2638.351 |
| B/MHz | 1648.983 | 1418.007 | 1693.999 | 1646.522 | 1421.043 | 1410.402 | 1784.632 | 1818.541 |
| C/MHz | 1457.303 | 1250.349 | 1463.153 | 1434.2356 | 1242.341 | 1234.704 | 1363.514 | 1377.309 |
| |μa| (D) | 3.0 | 3.9 | 1.6 | 0.6 | 1.4 | 0.4 | 1.2 | 2.1 |
| |μb| (D) | 2.3 | 2.4 | 1.2 | 1.4 | 0.2 | 1.0 | 0.3 | 1.0 |
| |μc| (D) | 1.0 | 0.8 | 1.8 | 1.1 | 0.1 | 2.1 | 0.1 | 1.4 |
| χaa (MHz) | 2.09 | 2.76 | –1.24 | –2.47 | 2.93 | 0.38 | 2.17 | –1.49 |
| χbb (MHz) | –3.70 | –4.58 | –0.25 | –0.03 | 1.83 | –0.78 | 2.64 | –0.53 |
| τ1b/deg | 43.3 | 51.8 | –61.3 | –49.4 | –66.4 | –62.2 | 165.8 | –177.2 |
| τ2c/deg | –80.1 | 171.7 | 61.7 | 73.1 | 172.7 | 176.7 | –74.3 | 62.1 |
| ΔIrmsd amu·Å2 | 3.2 | 174.2 | 26.5 | 14.0 | 175.5 | 183.6 | 88.2 | 94.5 |
a
kJ/mol relative to the global minimum 1a.
b
Backbone torsional angle (NC2C1O).
c
Backbone torsional angle (NC2C1C3).
d
Root-mean-square averages of the differences between observed and calculated moments of inertia, where ΔI = [Ix(exp) – Ix(calc)] and x = a, b, and c for each isotopologue.